Process of rendering soluble in water the nickel and copper contained in sulfid ores and mattes.



UNITED STATES PATENT OFFICE.

WALTER S. GATES AND HERBERT H. DOW, OF MIDLAND, MICHIGAN, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE ONTARIO NICKEL COMPANY, LIMITED, OF WORTHINGTON, CAN- ADA, A CORPORATION OF CANADA.

PROCESS OF RENDERING' SOLUBLE IN WAT ER THE NICKEL AND COPPER CONTAINED IN SULFID ORES AND MATTES.

.N aven e.

, Specification of Letters Patent;

Patented Dec. 24;, 1907."

I and HERBERT H. Dow, citizens of the United States, residents of Midland, county of Midland, and State of Michigan, have invented a new and useful Improvement in Processes of Rendering Soluble in Water the Nickel and Copper which are Contained in SulfidOres and Mattes, of which the following is a specification, the principle of the invention bein herein explained and the best mode in whic we have contemplated applying that principle, so as to distinguish it from other inventions.

Our invention relates to a new and useful process of rendering soluble the nickel and copper contained in sulfid ores and mattes,

for instance, the usual pyrrhotite ores.

Our invention is deslgned to precede in operation and cooperate with our improved process of separating metals in solution, described in our a plication for U. S. Letters Patent, Serial N 0. 300,728, filed Feby 12,

1906, the steps of this process being adapted to bring the valuable metals into a conditionwhere they may be acted upon by'the process described and claimed in the above-entitled application.

Our invention consists in steps hereinafter fully described and specifically set forth in the claims.

The following description sets forth in detail one mode of carrym out the invention, such disclosed mode constituting but one of various ways in which the principle of the invention may be used. 1

- The first step in our improved process is to crush and grind the ore, and then mix the same with salt, either sodium chlorid or the chlorids of the alkaline earth metals, or ferric chlorid, the chlorin and hydrochloric acid furnished by such chlorid treatment being agreat help in the subsequent roasting of the combination of copper, nickel and iron sul-' and chlorids of copper and nickel which are soluble in the above-named reagents. Furthermore, a moderate roasting temperature does not decompose the sulfates and chlorids of nickel and cop er which have been obtained at any time rom a previous stage of the roast. And, again, a moderate roasting temperature converts a large amount of the iron present in the ore directly to ferric oxid, and, also, any normal and basic iron salts, such as Fe (SO,)3 and Fe,,(SO,)3.I*e,,O which are present at, any time from a previous stage of the roast are decomposed to ferric oxid, which is insoluble in the above-named reagents. At the first stages of the roasting step, the gases given ofi are S0,, any iron which is soluble is in the ferrous state; in the later stages of the roasting ste s the gases iven off are Cl in excess, S0,, H 1, and the men is in a ferric condition. The roasting step is not discontinued when the chlorin fumes first appear,.but is continued to advantage for some time after such apearance, in order. to convert as much of the iron as possible to the condition in which it is insoluble in water, and in halogens." We find that the amount of chlorid necessary is from 10 to 15% of the weight of. the ore. We aim to oxidize the bulk of the sulfurin the ore, the reason for which will be fully explained later, and the length of time required to accomplish this is dependent upon the fineness of the ore and t e fre uency with which a fresh surface is expose to the ox1- The mixed acids from be collected if desired under the render the dizi'ng conditions. the roastin step may in any desirable way. Roastin'Lg conditions above enumerated w' l followin pro ortions, within wide limits, of

the tota of t e different metals present soluble in water, viz:

Iron about to 4% Copper-.- 5O to 75% Nickel- 20 to 40%? The nextstep is to lixiviate the roasted ore with water'in order to remove these solublesalts of iron, copper and nickel in a solution,

which is faintly acid. This extraction can be effected in any suitable leaching vats with false bottoms. We thus recover a portion of the values contained in the sulfidjores or mattes, and the second part of our process is to treat the residues from the water extraction with a dilute solution of free halogen in order that we may render soluble a great part of the remaining values not obtained by the water extraction. We have discovered that a considerable part of the nickel and copper remaining insoluble inwater after the roasting step is in such condition as to be easily attacked and dissolved by free halogens even in dilute solutions, without at the same time dissolving lar e amounts of iron. This is true if substantia y all the sulfur in the ore has been oxidized during the roasting step; otherwise, any suhid remaining uses up a large amount of free halogen in becoming oxidized, and-thus gets into solution a large amount of iron since the latter predominated in the original sulfid; and, furthermore, there is an additional loss of efficiency in the halo en treatment, due to the subseuent disso ving by the halogen of the sulset free bythe action of the halogen on the sulfid, and such action of the halogen upon the sulfid produces a large amount of sulfate which must later be removed, in order that the insoluble anodes in the cell used for setting free the halogen during the following etc may not be subjected to its bad effect. f the halogens, we have found that bro- .min acts more ra idly than chlorin, andalso dissolves the. nic el and copper more completely, and the effect of this more efiicient action of bromin can be easily attained by adding-a little bromid to the brine solution containing the free chlorin, thus causing the free halogen existing at any time to be bro- 111111.

Our im roved method of treating the ore residue with free halogen is to electrol ze a brine, preferably containing a trace 0 bromid, in a suitable cell, preferably without a diaphragm, and then bring this brine, now

containing free halogen, into contact with,

the ore residue, whereby the free halogen is taken 11- by the ore with'the formation of soluble aloids of copper and nickel. This brine,-now deprived of a large part of its-free halogen and containing in its place the soluble halogen salts of copper and nickel, is removed from the ore and again assed through the cell, in which it is again e ectro lyzed, with the result that at the ositive pole the halogen is again set free, an at the ne ative pole the corresponding amount of valuable metals is according to the follbwing reactions: v

H,O+NaCl+NaBr-|-current NaOH+Br Na0H+(FeCuNUchlorids- (FeCuNl)hydrates+NaCl. The proportion of salt and the voltage used could be so adjusted that the metals would be deposited at the negative pole in the metallic state, but there would also be thrown down by this neutral solution considerable recipitated as hydrates trainee basic iron precipitate, containing copper and nickel, which we have found to be an undesirable form for the purposes of our process. The brine is a convenient medium in which to create and carry the free halogen, and by which to leach the ore for the solvent action of the halogen. Furthermore, it has the advanta e of a low resistance to the current in the'ce 1. Any approved form and grouping of ap aratus for accomplishing the abovedescri ed halogen treatment may be utilized, and we find it convenient and preferable to use as leaching vats the same ones in which the ore is lixiviated with water, so that the ore need not be moved before the halogen treatment, these vats being preferably made of wood coated with tar or asphalt to prevent their destruction by the free halogen. The cell may be constructed of the same material. These vats, as mentioned above, are provided with a false bottom and connected with two conduits to a cell adapted to contain the brine, and having insoluble electrodes, preferably of carbon. Circulation from the-cell to the vat and vice versa may be eifectedin any suitable manner. The bromid brine enters the cell and is electrolyzed during its passage therethrough to the point Where a small proportion of halogen is set free; thebrine then passes to the ore in the vat, while assing through which the free bromin v in the brine is taken up in dissolving the copper and-nickel remaining in the ore residue, producing soluble bromids of such metals in the place of the free bromin. The brine, thus partly or completely deprived of its free bromin, is then returned to the cell, carrying with it the soluble bromids. Then it is again electrolyzed to the extent of freeing the bromin again from its combination with the valuable metals, said metals being deposited in a layer about the cathode in the orm of hydrates, the brine with its free bromin again being returned to the vat to take up further values from the ore residue. By means of this continuous circulation the percentage of free halogens is kept low, which provi es a gpod ampere efficiency, and, fur.- thermorejt ere are not dissolved from the ore large amounts of substances which have no value, 'or substances which might present a positive disadvantage by their presence in the solution, such as iron and aluminium,

and sulfate formed by the action of halogen on the-sulfur set free by the halogen action upon imperfectly roasted cores of ore particles' Furthermore, bythis continuous circulation, the same bromin acts repeatedly with slight loss and the-same brine is used repeatedly. We do not thus secure pure hyaim merely to obtain the values from the ore residues, and deposit them in the cell as mixed hydrates. This accumulation of mixed hyates in the cell is periodically .drates in the cell, but by this treatment I erases ore, together with a small percentage of the iron; and the [iron content of the original 4 water solution causes it to take up the copper and nickel in the'mixedhydra'ces, according to the method outlined in our above mentioned application No. 300728. The halogen treatment is continued with a vat of ore so lon washe and discarded.

The halogentreatment (nd follow the roasting step without the intermediate lixiviating with Water, if it were so desired, but there is a serious disadvantage in doing this,

in that the first water solution contains com' paratively much sulfate, which makes it impracticable to use carbon electrodes.

In all the above treatments we have discovered that cobalt acts in the same manner as nickel and in every way is an equivalent of the latter. v

, We are well aware that methods have been used in which some steps similar to ours are disclosed;-for instance, processes for copper ores, in which the ore is roasted with salt, giving 75% of copper soluble in hot water and 25% soluble, 1n hot mixed acid derived from the roastingsteps; also processes for nickel in which the ore is roasted with salt, giving some nickel and copper soluble in hot water; but we are not aware that such roasting and leaching steps have been combined with treatments which we have hereinbefore described, namely, the combination of the recovery of part of the values by roasting 1 and lixiviating, and the recovery of further values by treatment with a free halogen, simultaneous separation of metallic hydrates, and the addition of such hydrates to the solution derived from the lixiviation of the roasted ore whereby practically all the copper and nickel in the ore are obtained in forms most suitable for treatment according to our process outlined in the above-mentioned application No. 300728." We wish to point out that there is a great advantage in the above treatment over otherprocesses in the matter of handling the corrosive acid-and copper solutions in the cold.

Having thus described our invention in detail, that which we particularly point out and distinctly claim, is:

1. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in-roastingthe ore; and, then, treatingthe same with a haloid solution containin free halogen.

a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in roasting the ore; and, then,

as economic, and then that ore is treating the same with a haloid solution containing free bromin.

3. In a process of rendering soluble in water the nickel and copper which are contained-in sulfid ores and mattes, the steps which consist, in roasting the ore; lixiviating with water; and, then, treating the residue with a haloid solution containing free halo:

gen.

4.-In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores andmattes, the steps which consist, in mixing the ore with a chlo- 'r-id; roasting said mixture; and, then, treatingthe same with a haloid solution containing freehalogen.

5. In a process of rendering soluble in water the nickel and. copper which are contained in sulfid ores and mattes, the steps which consist,-in mixing the orewith a chlorid; roasting said mixture; and, then, treating the same with a haloid solution containing free bromi'n.

6-. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, thesteps which consist, in mixing the ore with a chlorid; roasting said mixture; lixiviating with water; and, then, treating the residue with free halogen.

7 In a process of rendering soluble in waterthe :nickel and copper-which are con.- tained in sulfid ores and mattes, the steps which consist, in mixing the ore with a chlo-- rid; roasting said mixture; lixiviating with water; and, then, treating the residue with free bromin.

8. In a process of. rendering soluble in water the nickel and copper which are con-' tained in sul'fid ores and mattes, the steps whichconsist, in roasting the ore; lixiviating treating the residue with a brine solution containing free halogen, thereby obtaining haloids; and, then, electrolyzing said brine, thereby setting halogen free and simultaneously creating insoluble products.

9. In a rocess of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in roasting the ore; lixiviating; treatmg the residue with a brine solu-' tion containing free bromin, thereby obtaining bromids; and, then, electrolyzing said brine, thereby setting bromin free and s1mul-' taneously creating insoluble products.

10. In a rocess of rendering soluble in water the nlckel and copper which are contained in sul'fid ores and niattes, the ste s which'eonsist, in mixing the ore with a ch 0- rid; roasting said mixture; lixiviating with water; treating the residue with a brine solution containing free halogen, thereby obtaining haloids; and, then, electrolyzing said brine, thereby setting halogen free and, simultaneously creating insoluble products.

11. In a process of rendering soluble in Water the nickel and co per which are contained in sulfid ores and mattes, the steps, which consist, in mixing the ore with a chlorid; roasting said mixture; lixiviating with water; treating the residue with free halogen, thereby obtaining haloids; setting free the halogen from the latter and simultaneously creating insoluble products trolyzing a brine containing said haloids; and, then, dissolving such insoluble prod ucts.

12. In. aprocess of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in roasting the ore lixiviating; treating the residue with a brine solu- I own containing free halogen, thereby obtaining haloids electrolyzing said brine, thereby setting halogen free and simultaneously creating insoluble products ;'and, then, causing the halogen thus set free to act upon more residues from the lixiviating treatment.

13. In a process of rendering soluble in water the nickel and cop er which are contained in sulfid ores and mattes, the steps which consist, in roasting the ore; lixiviating; treating the residue with abrine solution containing free bromin, thereby obtaining bromids; electrolyzing said brine, thereby setting bromin free and simultaneously creating insoluble products; and, then, causing the bromin thus set free to act .upon more residues from the lixiviating treatment.

14.-In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores an mattes, the steps which consist, in mixing the ore with a chlorid; roasting said mixture; lixiviating with water; treating the residue with a brine solution containing free halogen, thereby obtaining haloids electrolyzing said brine, thereby setting halogen free and simultaneously creating insoluble products; and, then, causing the halogen thus set free to act upon more residues from the lixiviating treatment.

15. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in mixing the ore with a, lixiviating I with freechlorid; roasting said mixture; with water; treating the residue halogen, thereby obtaining haloids; setting free the halogen from the latter and simultaneously creating insoluble valuable products in a cellby electrolyzing a brine containing said haloids; dissolying such insoluble prod ucts; and causing the halogen set free as above to act upon more residues from the lixiviating treatment.

16. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the ste s which consist, in recovering part of t e values by roasting and lixiviating; and,

in a cell by elec-' with a ch s ite then, recovering further values by e1ectro-= lyzing in a cell a brine containing bromids, causing the bromin that is set free by said electrolyzing step to act upon the residues of said lixiviating step, thereby forming more values by roasting and lixiviating; and, then,

recoverin further values by electrolyzing in a cell a alogen brine containing bromids formed by the action of free bromin upon the residues from a lixiviating treatment; causing the bromin that is set free by said electrolyzing step to act upon other ortions of such residues to form more bromi s, and the metals in said bromids from which the bromin has been freed to form insoluble products in the cell.

18. In a process of rendering soluble in water the nickel and copper which are con tained in sulfid ores and mattes, the ste s which consist, in recovering part of t .e values'by roasting and lixiviating and, then, recovering further values by forming haloids of the valuable metals contained in the residue from such lixiviating step; continuously electrolyzing in a cell a brine containing said haloids, thereby setting halogen free and forming insoluble products of the values in said haloids, and causing the halogen thus set free to act upon other portions of the residue from the lixiviating ste 19. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the ste s which consist, in recovering part of t e values by roasting and lixiviating and, then, recovering further values by forming haloids with the valuable metals contained in the residues from such lixivi'ating treatment; continuously electrolyzing in a cell a brine containing said haloids, thereby setting halogenfr e and causing the values in said haloids to form insoluble roducts in the cell, causin the halogen tlius set free to act u on ot er portions of the residue from such ixiviating step, and dissolving said insoluble products.

20. In a process of rendering soluble in water the nickel and copperwhich are contained'in sulfid oresand mattes, the ste swhich consist, in recovering a portion of tie values by rinding the ore; mixingthe same orid; roasting the mixture and lixiviating with water; and, then, recoverin further values by treating the residue with free bromin; continuously electrolyzing in a cell a halo en brine containing brornids of the valuab e metals formed by such free erases bromin treatment, thereby setting bromin free to act upon other ortions of such residues andcreating inso uble products in the cell of the valuable metals contained in said bromids from which the bromin has been freed; dissolving such insoluble products; and recovering the values from such solution.

21. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in roasting the ore; lixiviating; treating the residue with free halogen; and, then, electrolyzing in a cell the resultant halogen salts with a simultaneous preci itationof metallic constituents in inso uble form, and the liberation of free halogen.

22. In a process of rendering soluble in Water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in mixing the ore with a chlorid; roasting the mixture; lixiviating;

treating the residue with free halogen; electrolyzing the resultant halgen soalts in a cell with a simultaneous preci itation of the metallic constituents in inso uble form and the liberation of free halogen; and, then, dissolvi such insoluble roducts.

23. n a process 0 rendering soluble in Water the nickel and cop er which are contained in sulfid ores and mattes, thesteps which consist, in mixing the ore with a chlorid; roasting the mixture; treating the same with free b'romin; continuously electrolyzing in a cell a halogen brine containing bromids of iron, copper and nickel formed by such free bromin treatment, thereby I setting bromin free to act upon other portions of such roasted mixture and creatin insoluble roducts of iron, copper and niche in the ce I; and, then, dissolving such insoluble products.

24:, In a process of rendering soluble in water the nickel which is containedin sulfid ores and mattes, the steps which consist, in mixing the ore with a chlorid; roasting the mixture; treating the same with free bromin, thereby obtaining nickel bromid; and, then, setting free the bromin from said bromid and simultaneously creating nickel hydrate in a cell by electrolyzing a halogen brine containing said nickel bromid.

25. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the ste s which consist, in recovering a portion of t e values by roasting and lix1viating; and, then, recovering further portions of the valuable metals by converting them from the residue into haloids and then into hydrates; and, then, adding such hydrates to the original water solution obtained by said lixiviating step. a w

26.} n a process of rendering soluble in water the nickel which is contained in sulfid ores and mattes, the steps which consist, in mixing the ore. witha chlorid; roastingsaid mixture; lixiviating with water; treating the residue with free bromin, thereby obtaining nickel bromid; and, then, setting free the bromin from said bromid and simultaneously creating nickel hydrate in a a cell by electrolyzing a halogen brine containing said nickel bromid.

27. In a process of rendering soluble in Water the nickel and copper which are contained in sulfid ores and mattes, the steps which consists, in mixing the ore with a chlorid; roasting the mixture; lixiviating; treating the residue with free halogen; electrolyzing the resultant salts of nickel, copper and iron in a cell with the simultaneous precipitation of the nickel, copper and'iron and the liberation of free halogen.

28. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the steps which consist, in mixing the ore with a,

chlorid; roasting the mixture ;jlixiviating treating the residue with. free bromin; electrolyzing the resultant bromide in a cell with the simultaneous precipitation of the nickel, copper and iron as hydrates and the liberationoi free bromin.; and, then, adding such hydrates to the original water solution obtained by said lixiviating step.

- 29. In a process of rendering soluble in water the nickel and copper which are contained in sulfid ores and mattes, the ste s which consist, in recovering a portion of t e values by roasting and lixiviating; and,-

then, recovering further portions of the valuable metals by convertin them into bromids, electrolyzin in a cel a halogen brine containing suc bromids, with. the formation of hydrates of the valuable metals; and, then, dissolving the hydrates resulting from said electrolyzing treatment.

30. In a process of rendering soluble in water the nickel whichv is contained in sulfid ores and mattes, the steps-which consist, in recoverin a portion of the values by roasting and lixiviating; and, then, recovering further values by treating the residue with a brine solution containing-free halogen; and

electrolyzing the resultant halogen salts of nickel to. form nickel hydrate.

31. In a process of rendering soluble in water the nickel which is contained in sulfid ores and mattes, the 'ste s which consist, in mixing the ore with a cilorid; roasting the mixture; lixiviating; treating the residue with a brine solution containing free bromin; and electrolyzing the resultant bromin salts of nickel with the formation of nickel hydrate and the liberatijon'of free bromin.

32. In a process of rendering soluble in Water the nickel and copper which are condissolving such insoluble products; and re- 10 tained in sulfid ores and mattes, the steps covering the values from such solution. which consist, in disintegrating the ore; 'Signed by us, this 14 day of March 1906.

-mixing the same with sodium chlorid;

5 roasting the mixture; lixiviating; treating, the residue with free bromine created by electrolyzing in a cell a halogen brine con- Attested by': mining bromids of the valuebie metals, G.- L.'. CAMP,

thus forming insoluble products in the cell; vC. M. YOUNG, 

